Abstract: This study aims to develop the Green Contact Index (GCI) questionnaire and test its validity and reliability for measuring the natural exposure level of teenagers.With the symptom of nature-deficit disorder and the definition of horticultural therapy as theoretical basis, GCI was explored by literature analysis, open questionnaire survey and semi-structured interview.A total of 374 junior high school students completed the formal test, the ages ranging from 12 to 13, with an average of 12.5 years.The results showed that the GCI questionnaire has good reliability and validity.Exploratory factor analysis showed that the questionnaire has four dimensions, namely, green expectation and emotion, appreciation and plant care, plant harvesting and structured and polygraph.Confirmatory factor analysis also supported the four factor model to a certain extent, and the model fit indices are all above 0.88.The internal consistency coefficient of the whole scale is 0.88 and the split half coefficient is 0.88.The correlation validity with green environmental satisfaction is 0.42.These results all meet the requirements of psychometrics.Therefore, the GCI questionnaire can be used as an effective tool for measuring the level of youth green contacting, especially suitable for 12-13 year-old children.